Consider this a warning to anyone who didn't get the bundle.
Bought the A6M2 Zero. Ascended to 32k ft, unlocked the proper achievement, made a save.
Nosedive with the Zero at 32k - 580 kts, no achievement.
Nosedive with the Stearman at 32k - 500 kts, no achievement.
Nosedive with the Zero at 39k - 605 kts, no achievement.
Bought the P-51 Mustang. Curious if it was just the one needed piece of DLC before it would unlock.
Nosedive with the Zero at 39k - 605 kts, no achievement. (Pilot profile says 650, which is even worse.)
Nosedive with the Mustang at 39k - achievement pops at 420 kts.
So despite the fact that the Zero is capable of it, you explicitly need the P-51 Mustang to unlock this achievement.